huntingtons chorea, GCA, temporal arteritis

Question 1

what is huntingtons chorea

Answer 1

Neurodegenerative disease caused by malfunction in huntington gene (CAG repeats). causes neuronal cell atrophy - loss of GABA-neurgic neruones in caudate nucleus and putamen of basal ganglia
LESS GABA MORE DOPAMINE INCREASED MOVEMENT

Question 2

pathophysciology of huntingtons chorea

Answer 2

36 or more CAG triplet repeats - huntingtons protein build up in striatum - cell death - (STRIATUM ATROPHY)
loss of GABAnergic neurones in caudate nucleus and putamen of basal ganglia
less GABA = Dopamine no as regulated so increased to striatum = INCREASE MOVEMENT
GABA = a neurotransmitter inhibitor

Question 3

CFs of huntingtons chorea

Answer 3

prodromal phase - mild phsycotic and behavioural sympotoms (Depression personality chagne iritability)
late symptoms - chorea (explosive jerky movements) - hyperkinesia
rigidity
dysarthria
dysphagia
dementia
abnormal eye movemetns

Question 4

DDx of huntigtons chorea

Answer 4

wilsons
sle
LEVODOPA (parkinsons treatment to decrease GABA - too much decrease = other way)

Question 5

Dx of huntingtons chorea

Answer 5

genetic testing (over 35 cag repeats)
MRI - striatum atrophy

Question 6

Mx of huntingtons chorea

Answer 6

no tx to prevent prgoression
COUNSELLING - to patient and children (as ANTICIPATION)
BDZs = benzodiazepines - increase GABA effect
tetrabenazine - for chorea - depletes dopamine
risperidone - antiphyschotic
SSRI setraline - antidepress
VALPROIC ACID - anti convulsant - increases GABA

Question 7

Huntington’s genetic features

Answer 7

Autosomal dominant
100% penetrance,
gets more and more repreats with every generation - starting earlier (anticipation)
= at least 36 CAG repeats

Question 8

Giant cell arteritis

Answer 8

granulomatous inflamation of bv wall (vasculitis) of temporal artery

Question 9

what is giant cell arteritis assos with

Answer 9

polymyalgia rheumatica (50%)

Question 10

epid of GCA

Answer 10

most common type of vasculitis in the elderly

Question 11

What are the symptoms of GCA?

Answer 11

Temporal pulsating headache
Scalp tenderness 
Jaw claudication 
Amaurosis fugax 
Systemic: fatigue, fever, myalgia, (WL, depression)

Question 12

How is GCA investigated?

Answer 12

Pulseless temporal artery
Raised ESR and CRP
Biopsy within 1 week (skip lesions)

Question 13

What is the treatment of GCA?

Answer 13

Prednisolone 12 months
Visual symptoms - IV methylprednisolone 3 days
PPIs and bisphosphonates from long term steroid use

Question 14

What condition presents in 50% GCA patients?

Answer 14

Polymyalgia rheumatica

Question 15

What is temporal arteritis?

Answer 15

Inflammatory granulomatous vasculitis of large cerebral arteries

Question 16

sign of GCA

Answer 16

palpable tender non pulsatile temporal artery

thickened

Question 17

why get amaroux fugax in GCA

Answer 17

extensitioin of the vasulitis to the opthalmic artery

Question 18

DDx of GCA

Answer 18

migraine
tension headache
trigeminal neuralgia
polyarteritis nodosa

Question 19

Dx of GCA

Answer 19

bloods - high ESR/CRP

temporal artery biopsy *** - necrotising, skip lesions (within a weeK)

Question 20

What is trigeminal neuralgia?

Answer 20

Paroxysms of intense, debilitating pain in the distribution of the trigeminal nerve (CN5)

Question 21

what does the trigem nerve split into

Answer 21

5. 1 - opthalmic
6. 2 - maxillary
7. 3 - mandibular

Question 22

what is the moto fuction of CN5

Answer 22

trigeminal = muscles of mastication

Question 23

RF of trigeminal neuralgia

Answer 23

HTN

Question 24

What is the peak age of onset of trigeminal neuralgia?

Answer 24

50 years

Question 25

What causes the pain in trigeminal neuralgia?

Answer 25

Compression of the trigeminal nerve causing demyelination and excitation of the nerve = PAIN

Question 26

What are the characteristics of trigeminal neuralgia?

Answer 26

Sudden, unilateral paroxysms of knife-like/electric shock pain
Mandibular –> maxillary and ophthalmic
Lasts seconds to minutes
Triggers- eating, shaving, talking

Question 27

Trigeminal neuralgia Causes

Answer 27

Primary idiopathic.
relating to age
secondary: skull abnormality, malignancy, MS

Question 28

How is trigeminal neuralgia diagnosed?

Answer 28

MRI to exclude secondary causes or other pathologies

Question 29

What is the treatment of trigeminal neuralgia?

Answer 29

Carbamazepine - membrane stabalizer = less freq impulses (antiepilpetic aswell = tonic-clonic and partial seizures)
Neurovascular decompression